微柱流动注射同位素稀释电感耦合等离子体质谱法测定海水中的痕量铅

Determination of Trace Lead in Seawater by Isotope Dilution Method Coupled Micro-column Flow Injection and Inductively Coupled Plasma Mass Spectrometry (FI-ICP-MS)

本文建立了用微柱流动注射与电感耦合等离子体质谱联用的同位素稀释分析方法。在优化条件下铅的检出限(3σ,n=6)为0.22ng/mL,对标准水样和加标海水的测定结果表明,方法的回收率分别为104.0%和94.8%。该法具有同位素稀释测量准确度高、操作简便的优点,能实现在线分离、富集和测定,及减少样品处理引入污染等特点,可应用于生物、环境等高盐样品中铅的在线分离测定。

An isotope dilution method, in which the chelating reaction of lead with 8hydroquinoline5sulfonic acid (8HQS) was used, for measuring trace lead in seawater by microcolumn flow injection and inductively coupled plasma mass spectrometry (IDFIICPMS) was established. The parameters of the hyphenated technique, such as the concentration of 8HQS, sample loading time and speed, washing time, eluent acid concentration and instrumental parameters of FIAICPMS were optimized and selected. The detection limits of this method estimated with threefold standard deviation of the procedure blank was 0.22 ng/mL. The recovery test of spiked Pb standard in seawater was 94.8%. In order to assess the accuracy of this method, standard reference water (GBW 08607) was used. The result is in good agreement with the certified value and the recovery was 104.0%. This method is recommended to determine the trace lead concentration in high salt matrix of samples.